Fast Degradation of Azo Dyes by Using Cu-based Metallic Glasses

Advances in Materials
2021; 10(1): 1-4
http://www.sciencepublishinggroup.com/j/am
doi: 10.11648/j.am.20211001.11
ISSN: 2327-2503 (Print); ISSN: 2327-252X (Online)

Fast Degradation of Azo Dyes by Using Cu-based Metallic
Glasses
Xiao Chen Xu1, 2, Ke Qiang Qiu1, *
1
    Material Science and Engineering College, Shenyang University of Technology, Shenyang, China
2
    Mechanical and Power Engineering College, Yingkou Institute of Technology, Yingkou, China

Email address:
*
    Corresponding author

To cite this article:
Xiao Chen Xu, Ke Qiang Qiu. Fast Degradation of Azo Dyes by Using Cu-based Metallic Glasses. Advances in Materials.
Vol. 10, No. 1, 2021, pp. 1-4. doi: 10.11648/j.am.20211001.11

Received: January 11, 2021; Accepted: January 20, 2021; Published: January 28, 2021

Abstract: Wastewater containing azo dye has become a main harm in water pollution. Therefore, development of environment
friendly materials with efficient purifying capacity seized more and more attention of people devoting to dye wastewater
processing. On the other hand, advancement of metallic glasses in degrading organic water contaminant has also received wide
concern. Cu-based amorphous alloy has excellent corrosion resistance and good stability in the process of degradation of azo
dyes In the present thesis, single roller melt-spinning method Cu-Zr-Al-Y metallic glasses is applied so as to investigate
degradation of azo dye Direct Blue in acid and alkaline solution. It is concluded that when the value of it is 2, 25µm ~ 30µm thick
stripes of non-crystalline structures will be formed. With variation of the pH, rate of degradation will also change. The
degradation rate in acidic solution is higher than that in alkaline and neutral solution. This is due to the fact that Azo bond and
Cu-based amorphous alloy in dye molecule requires quite low activation energy to react, which makes degradation easier to
proceed and thus macroscopic decoloration is also quickened. After the treatment of wastewater, white corrosion products will be
produced on the surface of amorphous strip. It will affect the degradation effect.
Keywords: Cu-based Metallic Glasses, Direct Blue Azo Dye, Degradation

1. Introduction
   In the last few years, the discharge of industrial wastewater,      could degrade the azo dye of acid orange II dye solution [9,
especially printing and dyeing wastewater, has caused great            10], and degrading effect of it is better than
harm to the natural environment and people's living water, so          homo-componential crystalline alloy and commercial iron
treatment of wastewater has become urgent. At present, there           powder Wang [11] produced Mg-Zn-Ca powder through
are many methods to degrade dye wastewater, such as,                   ball-milling method, and it turns out that Mg-Zn-Ca powder
Activated carbon adsorption method, chemical oxidation                 bears stronger degrading and decay resistance properties than
method, and biodegradation method. However, it is necessary            its corresponding crystalline-state powder. Amorphous-state
to find a method that is efficient, cost-effective and                 Mg-Zn-Ca powder also shows a superior reacting efficiency in
environmental friendly to solve the problem, from the                  degrading the Congo Red dye [12].
standpoints of both resource conservation and environmental               We studied the reactivity of Cu-Zr-Al-Y metallic glasses in
remediation. Therefore, besides its application value in               degrading Direct Blue azo dye solutions. The influence of pH,
mechanics, magnetic property, decay resistance etc,                    reaction temperature, and dosage has been studied. The
non-crystalline material is also known as a functional material,       reaction mechanism has been studied based on the evolution
and can be used as catalyzer [1, 2], biological material [3, 4],       of surface morphologies and the compositions change for the
Soft magnetic material [5, 6] and in magneto caloric effect [7,        metallic glass ribbons.
8]. It is recently discovered that, Fe—Si—B amorphous alloy

2                  Xiao Chen Xu and Ke Qiang Qiu:       Fast Degradation of Azo Dyes by Using Cu-based Metallic Glasses

2. Experimental                                                           3. Results and Discussion
2.1. Reactivity Measurements                                              3.1. Characterization of the Cu46Zr45Al7Y2 Catalyst

   All experiments were conducted in 100mL beakers, which                    Figure 1 shows the XRD patterns of Cu46Zr45Al7Y2
were placed in a magnetic stirrer. During the reaction, the               metallic glass ribbonss. It can be seen from the figure that the
solution was rod-stirred at a xed speed. At present time intervals,       alloy strip is completely amorphous, and there are two obvious
3 mL aliquots were removed with a syringe and altered with                diffuse reflection peaks at the interval of 30-50° and 60-75°,
0.45 mm membranes [13]. The altered samples were pipetted                 which is the typical structure of amorphous alloy.
out and subjected to UV-vis spectrum scanning. The reacted
amorphous alloy strips were recycled and used for the
degradation of dye wastewater again to test the reusability of
amorphous alloy in the degradation of dye wastewater. The
mass of amorphous alloy strips used in each experiment was 1.0
g, the volume of was 30mL, the initial concentration of Direct
Blue solution was 0.1g/L, and the solution temperature was
kept at 40°C in the degradation experiment, and the
experimental parameters remained unchanged unless specified.
The acidity of the solutions was tuned by adding 1 M HCL
solution or 1M NaOH solution. For each time, 30 mL Direct
Dlue solution was put into the 100 mL beaker for reaction test.
The temperature was controlled by magnetic stirrer.

2.2. Fabrication and Characterization

   The alloy ingots with nominal compositions of
Cu46Zr45Al7Y2 were prepared by induction melting the                             Figure 1. XRD patterns of Cu46Zr45Al7Y2 amorphous ribbons.
mix-tures of pure Cu, Zr, Al, Ymetals under high purity argon
                                                                          3.2. The Reactivity in Solutions with Different pH
atmosphere. The Cu46Zr45Al7Y2 metallic glass ribbons were
fabricated by single roller melt-spinning method under the                   Figure 2 shows the effect of pH value on degradation
protection of argon atmosphere [14]. The atomic structure of              efficiency from azo dyes by using Cu-Based amorphous alloys.
the ribbons was verifified by X-ray diffraction.                          The pH of the solution plays an important role in the
                                                                          degradation of the dye. A slight change in pH will alter the
2.3. Mechanism Analysis
                                                                          degradation of the dye by the material. For most dye
   The morphology and structure of the ribbons before and                 wastewater, the pH is in the range of 2–10. In this work,
after degradation were examined by scanning electron                      therefore, we chose to degrade the Direct Blue at pH = 2, 7 and
microscopy (SEM) and XRD. The surface compositions of                     10. Figure 2(a) shows the UV absorption spectra of Direct
ribbons was also examined by energy dispersive spectroscopy               Blue 6 dye by using Cu46Zr45Al7Y2 amorphous ribbons. It can
(EDS) equipped on the SEM machine. [14] UV-vis spectra of                 indicate that the dye is completely degraded. The
azo dye solutions were recorded using an UV-vis                           characteristic absorption peak of Direct Dlue dye molecules
spectrometer.                                                             arises from 573 nm.

Figure 2. UV-visible absorption spectrum of the Drect Blue solution of the Cu46Zr45Al7Y2amorphous alloy strip at (a) pH=2, (b) pH=7and, (c) pH=10
trestedatdifferent treatingtime

   In acidic conditions, the UV-visible absorption spectrum of            that under acidic conditions, as the reaction time prolongs, the
the Drect Blue 6 solution of the Cu46Zr45Al7Y2 amorphous                  intensity of the absorption peak at 573 nm decreases
alloy strip degradation is shown in Figure 2 (a). It can be seen          continuously, indicating that the -N=N- structure of the direct

Advances in Materials 2021; 10(1): 1-4                                                                3

blue dye molecule is continuously destroyed until it is almost                   surface of the positively charged cu-based amorphous alloy,
completely decomposed. In acidic conditions, the Direct Dlue                     and as the pH of the solution increases, the positive charge is
dye can be completely degraded in 25 min with high                               reduced, the adsorption becomes more and more difficult, and
degradation efficiency. At pH=7, the UV-visible absorption                       the rate of subsequent degradation reaction is further slowed
spectrum of the Direct Dlue solution of the Cu46Zr45Al7Y2                        down.
amorphous alloy strip degradation is shown in Figure 2(b).
For every 10 minutes increase, the intensity of the absorption                   3.3. The Analysis of Surface Morphology
peak at 573 nm is less and less, which indicates that the                           In order to clarity the surface morphology of glassy ribbon
degradation rate of Direct Dlue is slower and slower,                            after cycle use on the degradation efficiency of simulated
especially when the reaction proceeds to 40 min, the change in                   images of glassy ribbons before degradation. As shown in
absorption peak intensity has been very weak at 573 nm.                          Figure 3(a) the surface of the amorphous strip is smooth
Figure 2(c) shows that in alkaline conditions, the Direct Dlue                   without cracks before degradation. Figure (b), (c) and (d)
degradation of becomes more difficult. This is because the                       show that there are white corrosion products on the surface of
Direct Blue solution is negatively charged in the acidic                         amorphous alloy after wastewater degradation [15].
solution, so when the p H is low, it is easily adsorbed on the

    Figure 3. SEM images of Cu46Zr45Al7Y2 glassy ribbon before degradation (a) and after the first cycle (b) and two cycles (c) and five cycles of use (d).

   So far, many researchers have used different amorphous                        Liaoning Province (Grant No. 2019ZD0373).
alloys to treat various kinds of wastewater. As shown in Table
1, the comparison of research results shows that Cu-based
amorphous alloy has outstanding advantages.                                      References
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